The cleaning of magnetic tape drives, in particular the magnetic heads and other transport components, has often been accomplished using a cleaning tape mounted in a cassette. The cleaning tape was specially made to clean the magnetic head and transport components. The user would load the cassette in the machine and let the machine run for a period of time. A prerecorded magnetic tape of known good quality would then be played in the machine to make a somewhat crude determination of the cleaning effectiveness.
One type of cleaning tape has a carrier film coated with magnetic iron oxide in a binder. This is a relatively abrasive tape which, although providing some cleaning effectiveness, is rather hard on the magnetic heads. Also, such cleaning tapes are not used in a wet format since conventional solvents attack the magnetic coatings.
U.S. Pat. No. 3,978,520 to Nowicki et al. discloses a magnetic cleaning tape having an abrasive magnetic coating of a particular character, the tape having a recorded video test pattern. The concept behind this invention is that the cleaning tape is run through the VCR until a clear test pattern is viewed, which indicates that the magnetic head is clean. The user then immediately halts playing of the cleaning tape to reduce excessive abrasion of the magnetic head. However, with this concept the cleaning tapes adds the same type of contamination the cleaning tape is attempting to remove, that is the abrasive magnetic coating and binder. Also, to remove the contaminants on the head, the abrasive magnetic coating must necessarily be quite abrasive itself. Since the quality of the recorded message is relative to the size of the abrasive magnetic particles, the relatively large particles necessary to create sufficient abrasion restricts the quality of the signal produced.